Physics Colloquium - Friday, Mar. 28th, 2008, 4:00 P.M.

E300 Math/Science Center; Refreshments at 3:30 P.M. in Room E200

Alan Fine
Department of Physiology and Biophysics
Dalhousie University faculty of Medicine

What we can learn about learning by watching synapses work

Although it is widely believed that the brain stores memories as distributed changes in the strength of connections ("synaptic transmission") between neurons, identification of the most important altered aspect of synaptic transmission has remained elusive. To solve this problem--which has persisted mainly because of the limitations of standard electrophysiological methods for monitoring synaptic transmission--my lab and others have been developing and applying optical methods to study synaptic function in semi-intact brain tissue. I will discuss briefly some of these methods, and some future directions in high resolution functional microscopy, and then describe recent experiments, using two-photon excitation fluorescence microscopy and fluorescent calcium-sensitive dyes, that have finally provided an unambiguous picture of the physiological changes in the synapse that are responsible for long-term enhancement and long-term depression of transmission.